UK's Johnson tries to stop health experts from commenting on aide Cummings

British Prime Minister Boris Johnson tried to stop his top medical and scientific advisors from answering reporters' questions about the behaviour of chief political advisor Dominic Cummings, saying they should not be involved in politics.Chris Whitty, England's chief medical officer, and Patrick Vallance, the government's chief scientific advisor, were repeatedly asked during a government news conference if a trip by Cummings from London to northern England set a bad example to the general publ